Dummies Guide to Screen Printing We talk to a lot of people who want to start screen printing but are not quite sure of the process and what’s really involved. So we thought we would write a high level process overview, to give you a little insight into how to get started. If you are a hobbyist, artist or commercial printer, the processes are pretty similar. We are going to work through the process of taking a blank garment to producing a garment with a printed logo………………..more details
The exorcist – how to get rid of ghosting on your screens
When you have finished your screen print run there are a number of next steps.
If you plan to use the design again then you need to wash the screen down. This will remove the ink from the screen but leave the exposed image. If your ink is water based a simple hose down is sufficient but a solvent ink will need screen wash. Make sure to use the right process for the ink involved.
‘Reclaiming’ is the act of striping the stencil from your screen in order to create a new stencil and start the printing process over again. If you are not going to print a design any more it’s time to reclaim your screen so that you can use them for something new.
Remove all tape from the mesh. Apply stencil strip with a cloth to both sides of the screen. Using a power washer to clean the screen thoroughly on both sides. Your screen is ready for reuse.
If there is still an image left on the screen this is called ‘ghosting’, this is an example of a screen with ghosting.
If there is any ghosting of the screen you can use a ghost remover / haze paste to remove them.
Haze Paste remover is a great solution if you have any ghosting left on your screen which is common when using waterbased inks as they dye the mesh. Our range includes the premium MacDermid Autohaze will deals with the most stubborn stains.
The finished screen after using this product Haze Paste..
Do you need basic screen printing training?
WPS are pleased to offer a range of screen printing training courses to suit your needs at an affordable price. Whether you are an absolute beginner and just want to know the basics or maybe struggling to print that multi colour complex job, wps have developed a number of courses, events and workshops to help you get the most out of screen printing.
Our courses can be tailor made to suit your specific needs, if you cannot find what you are looking for please contact us and we would be happy to design a package for you.
Have you got trouble with ghosting?
Does your screen look like this?
David Hand had an old screen and was so impressed with the results he sent before and after pictures. He told us “Hi. I just wanted to say the products I used to reclaim this screen were excellent. That pattern had been on there for six/seven years. Great stuff!“
This is the photo he sent us of the finished results
Haze Paste remover is a great solution if you have any ghosting left on your screen which is common when using waterbased inks as they dye the mesh. Our range includes the premium MacDermid Autohaze will deals with the most stubborn stains. There is a reason why we select our products because we want you to get the same kind of results. We have been very impressed by this product which is why we are authorised distributors. Haze Paste. on the Wicked Print Stuff website
Where does exposure fit in the screen printing process?
What emulsion should I use?
How long can I keep emulsion?
How do you get rid of pin holes?
How long should I dry my screen?
Let’s go back to basics. Screen printing is also a stencil method of print making in which a design is imposed on a screen of polyester or other fine mesh, with blank areas coated with an impermeable substance, and ink is forced into the mesh openings of the mesh by the fill blade or squeegee and onto the printing surface during the squeegee stroke.
Emulsion is the means of making impermeable substance. Light sensitive, thick liquid which coats the screen. When the screen is exposed the emulsion hardens and unexposed areas drop out to leave the stencil.
So you have your positive artwork
Now this process is one of the most tricky in screen printing and needs to be done thoroughly and carefully. Never skip on any step especially drying.
The first step is to degrease your screen
It is very important to degrease the screen prior to coating the screen with emulsion and exposing the artwork. A screen that is not degreased will have problems exposing and increase the chance of pinholes, the emulsion will not adhere to the screen properly and might washout before the image can be seen. The emulsion could also not wash out at all. Make sure you let it dry thoroughly before you coat it with emulsion.
Choosing your emulsion
There are many emulsions on the market and every printer will have their preferred type and brand. Some emulsions come pre sensitised and ready for use and some will need mixing. Our emulsion is a 2 part emulsion, its comes with sensitizer.
Shelf life is different depending on when the sensitizer is added . Separately both parts can last from 12-24 months. Once mixed the emulsion lasts 6-8 weeks (its life can be prolonged slightly if it is stored in a cold place, like the fridge).
Always make sure you have chosen the right emulsion if you are using Plastisol inks / Solvent inks you need a Solvent resistant emulsion like Ulano Proclaim or if you are using Waterbased inks you need a water resistant emulsion like Ulano 925wr. We also sell Autosol emulsion, which is a good dual purpose emulsion, it can be used with both waterbased and solvent inks.
Make sure you are doing all parts of the emulsion and exposure process in a light safe environment with NO outside or bright light. This includes mixing your emulsion, coating your screens, drying screens, exposure, and washout (as soon as screen is exposed as long as you wash it out straight away this is not a problem)..
A costing trough is the best way to get an even coverage of emulsion. Always check to make sure the coating trough has a straight edge and no damage otherwise you will get poor coverage and you can snag the mesh.
Here are a few things to watch out for if your images are not washing out correctly:
That you are not coating your emulsion too thick. One coat both sides should do it, with a nice even spread. There are sometimes where you may need some extra coats e.g. printing transfers and printing white onto a dark garment but you will need to adjust the exposure time.
That your film positive is very opaque and dark. If you hold it up to a light and can see through it, you need to double print your film to achieve a more opaque image.
That there is positive contact between your screen mesh and your positive film. If the film is not pressed completely against your mesh then you will get light reflection between your positive and your screen which will result in a blurry and not clear image. That’s why the glass is so important.
That you are exposing your screen for the correct amount of time, which will depend on the exposure system you are using. If you are unclear on exposure times please feel free to ask us. The simple run of thumb is – if the emulsions washes off too easily and you start to lose the stencil then the screen is underexposed and if after prolonged washing the stencil does not come through they you are likely to have overexposed the screen.
After you coat your screen, you want it to be COMPLETELY dry before you expose the screen.
Exposing the image
To transfer your image onto your screen you will need to use an exposure unit. There are many different exposure unit set ups on the market and each has a different light source. Each having different light sources. UV, halide and halogen are very popular in the UK. Our Wicked exposure lamp has a 1000 watt halogen light source and is provided will all waterbased and Plastisol kits.
We also sell Actinic and Metal Halide exposure units which are able to expose quicker (typical exposure time is 2 minutes for an Actinic unit and 16 minutes for the lamp depending on size of the screen) than the cheaper lamp solution. Some units include built in drying cabinets making the whole process a lot faster.
A very large part of your decision if you are new to screen printing will be your budget and space. Exposure units vary dramatically in price. The WPS Lamp is small and compact,
After exposing and rinsing out your exposure, you want your screen to thoroughly dry (and ideally harden your screen, by exposing it to the sun or your exposure unit) before inking and printing. This process is often called double baking.
Before inking you need to use blocking tape (can use brown tape or professional blocking tape) to cover up areas on the screen not covered by the emulsion. Also fix any pinholes either using blocking tape or using screen filler which is a liquid emulsion, make sure you choose the right one as there are different versions for solvent and water resistant stencils.
Now you are ready to print
When you get bigger there are other options like the Revolutionary Riso QS200 Designed for the Professional Printer which prints directly from your computer onto a screen. Then the whole process takes under 5 minutes!
The Ink is not giving a 100% coverage over my print?
Check that you have the proper off contact for the job at hand and that the screen is parallel to the platen. Typically you want your screen to be about 2 pennies or an eighth of an inch off your application.
If that is ok, assess the squeegee you are using – is it too soft for the ink type and mesh count too high?
Plus always remember to flood the image before you print.
When do you need heat/drying in the screen printing process?
• Drying emulsion before exposure
• Drying your screen after washing off the emulsion
• Touch drying after printing
• Drying between colours
• Fixing ink to fabric, The Cure
N.B. For printing posters and paper type flat work, you would use poster ink which is also an air dry ink. Either of the two textile inks may be used for screen printing shirts but the poster ink is used only for flat work and graphics printed on porous or glossy paper materials.
Drying emulsion before exposure
Screen drying cabinet or overnight, must be dust free and dark environment
Drying your screen after washing off the emulsion
You can blowdry it, or wave it in the air outside, or just let it air dry, but you should let it dry before making prints.
Touch drying after printing
Flash dryer, hand curer or heat gun
Drying between colours
Flash dryer, hand curer or heat gun
How hot does The Cure have to be and how long does it take?
Once you have finished your print, you will need to fully cure your garment. Simply drying the print does not mean that your garment is machine washable. In other words – The print will come out in the wash! The temperature must get hot enough to firstly evaporate the waterbased medium, then set the pigments.
This is a guide only
150F [66°C] Water begins to leave the ink
200F [94°C] Binder reaches lowest viscosity and maximum surface contact is made with the fabric
220F [105°C] Water begins to leave the ink rapidly
270F [133°C] Fifty percent of the water is gone and the binder and pigment start to cure
300F [150°C] Most of the water is gone and the binder-pigment combination is partially cured
300F [150°C] [for 30 seconds to a minute] Binder and pigment is cured
If you have used water-based ink:
Although waterbased ink dries to air, it takes a high temperature to cure water-based inks. You can cure the ink at 165°C (some are hotter) by using a flash dryer, tunnel dryer or heat press. It can take up to 2 minutes to cure waterbased inks. If you mix a catalyst with the ink you can cure the ink with a heat gun – but remember only really suitable for cold washes.
WPS waterbased inks need to be cured at 165 degrees or above. To cure your inks, you have a number of options. You can use a flash dryer, hand curer, heat press or tunnel conveyor dryer for this. If you are using a WICKED PRINTING STUFF flash dryer to cure your print, we recommend you measure the temperature of your print with a digital laser thermometer until it reaches the required temperature. Remember that it is important that the entire ink film thickness reach the specified cure/fusion temperature. Depending on the nature of your fabric it is recommended that you break this up into intervals of approximately 10-15 seconds and repeat 3-5 times as most garments cannot withstand such continuous heat in one go. If you are a busy printer, you will find that a conveyor tunnel dryer is a much quicker, more efficient and reliable way of curing prints.
If you have used Plastisol or other solvent-based ink:
In between the application of the different colours of your design you can use a heat gun to flash dry but to fully cure you should use a tunnel dryer, flash dryer or heat press. The ink needs to get to 150°C for typically 60 seconds. Glitter, reflective and white ink can sometimes take longer.
If you are printing more than one coat of ink for the same image, or printing a multi-colour image, you will need to flash cure your ink by using a flash dryer, hand curer or heat gun between each print. Flashing enables you to print one coat of ink on top of another – e.g., a color on a white base. You also might flash an ink to keep wet ink off the back of your screens. Some inks, such as glitters, metallics and high densities, are not designed to be printed “wet-on wet”. They should be “flashed” when printing in sequence. Once your print is dry to the touch you can apply your second coat or next colour. Most inks will “gel” (flash) when the ink film reaches 220°F to 230°F (104°C to 110°C). There are 3 factors that affect the “gel” or “flash” of the ink: the temperature of the flash, the distance of the flash from the printed image, and the time the printed image is exposed to the heat. As a rule, you want to flash the ink film until it is just “dry to the touch”. Over-flashing inks can cause inter-coat adhesion problems and make the inks very “tacky”. Check your flash cure unit to see if it has temperature and airflow controls. These can help you better control your flash cure process.
All Plastisol inks will not air dry and will therefore need to be dried by heat equipment. Plastisol inks will also need to be fully cured at 150 (or above) degrees, which is drying them to the correct temperature and length of time (typically 60 seconds), in order for the ink to not come off in the wash. A flash dryer will dry and cure the inks in 60 seconds and for longer print runs or larger set ups, a tunnel dryer is recommended.
Iron, Hot Air Gun, Flash Dryer, Hand Curer, Heat press, Tunnel Dryer,
Sun or outside clothes line – Can not be used as temperature is not hot enough.
Household clothes dryer – Can not be used as temperature is not hot enough.
Hand held hair drier – Can not be used as temperature is not hot enough.
Commercial Dryer (Laundromat) – Not a recommended method as temperature is not accurate and time limit can vary greatly on garment type. Garments left in too long may shrink or be damaged.
We manufacture the most comprehensive range of tunnel dryers in Europe ranging from the brilliant ‘Mini dryer’ to the top of the range dryers. The Mini Tunnel Dryer is ideal for the smaller workshop using a tabletop or small standalone carousel up to the top of the range WPS Panther Dryers which are ideal for screen printers with automatic presses or digital printers.
check our Mesh Guidelines – Choosing the right mesh for the best print
Have you got problems with poorly exposed screens?
Do you have pinholes, stencil breakdown, or poor quality prints?
Are you wasting production time and materials?
Also see our blog post Creating a screen using traditional exposure methods
Following our post last week about exposure timings taken from our FAQs we were asked for more details. Transfering your artwork onto a screen is the most complicated part of the screen printing process, do it incorrectly and you will create problems for yourself. Here we have an example of a design with pin holes.
The principle of the screen is that there is a mesh with little holes. The ink is forced through the little holes on to the substrate (t-shirt, paper, cap) underneath. We only want the ink to go through in certain places, in this case the red lettering. So we create a stencil where our design is black and the background clear and we use red ink. We put emulsion on the screen and expose the screen using the stencil. The emulsion hardens and blocks the little holes in the mesh where it reacts to the UV light. The stencil blocks the UV light in the areas of the design. If the exposure is not correct we can end up with some of the little holes not blocked at all (pinholes) or not to a correct depth or hardness. Then when the squeegee comes along and scrapes the ink along the screen, as well as forcing the ink through the mesh it also scrapes of a little bit of emulsion and makes more holes. This picture shows some pinholes just above the e.
So correct exposure is the key to getting a completely covered, really hard, good quality screen that will last for a long print run.
Most exposure lights and chemicals give you recommended exposure times but these can require fine tuning. The UV light has to harden the emulsion on BOTH sides of the screen. It is a chemical reaction between the emulsion and the UV light that hardens the emulsion. Where the emulsion is hardened the mesh is blocked. The stencil protects the emulsion from the light so when the screen is washed that part of the stencil allows the ink through the mesh.
If your screen is under exposed there is not enough emulsion is on the screen. Then as the squeegee rubs on the screen it removes the emulsion leading to problems.
In this example above the stencil is the red lettering. Therefore the clear area of the screen must be complete blocked by hardened emulsion. But we have some pinholes which means stencil filler or tape are required to block them. Correct exposure will stop this occurring.
Lamps age and whilst it might look like they are doing their job they are not producing enough UV to properly expose the screen
Most manufactures give timings for your lamp/emulsion but it is worth doing a step test at 2-3 month intervals to check for any degradation and so you can fine tune your exposure times.
A step test is a graduated exposure of your screen to see which time has the best results
You can get a step wedge or a Step Transmission Gray Scale,, but you don’t really need one. You can use a piece of thick cardboard to test exposure time. Start by burning the whole screen 1 minute less than the recommended time for your unit/emulsion. Then cover about an inch of the emulsion with the cardboard. Every 30 seconds, cover another inch of the emulsion by sliding the cardboard forward. Once the screen was fully covered by the cardboard, the test is complete. Wash out the screen to find which exposure time produced the cleanest result. Keep a record of this and then you can compare results in 2-3 months time.
A simple inexpensive unit like the WPS exposure unit has all the features you need.
Light Source: 1000 watt halogen light. More efficient than two x 500 watt light units, where the light can overlap and cause uneven exposure.
Adjustable Height: For adjusting the exposure unit
For 12″ x 16″ screens – 10 inches and expose for 6 minutes
For 20″ x 24″ screens – 20 inches and expose for 15 minutes
For 31″ x 24″ screens – 23 inches and expose for 20 minutes
Important: Foam is charcoal in colour to absorb the light and not to reflect the light as lighter colours will do. This will prevent sharp toothing on fine line work and text when exposing.
You will need to supply your own sheet of glass. The glass needs to be at least 6mm thick double glazed or 10mm thick either single/double glazed. The thicker the sheet of glass, the more heat from the lamp it will be able to withstand so you can reduce the distance of the lamp from the screen to reduce your exposure time.
This unit will do the same job as a unit costing £500.00+ it just takes a little longer to expose the larger screen.
For the professional printer requiring larger volumes the Heavy Duty Exposure Unit is more sutable.WPS sells a range of heavy duty exposure units manufacturer in the UK which come in three standard sizes and a number of variations to suit customer requirements. The three standard models have all the same features, powerful suction pump, touch up lights, safety switch etc. There are a number of power options available 1, 2, 3, 5 & 6 K/w versions.
Two controller options are available, a timer system which comprises a digital timer, and switch for the vacuum and fluorescent tubes as well as a power switch, or our Magellis PLC control system this incorporates an LCD display, time settings and all programable features are accessed from the screen. This unit can also incorporate a light integrator which compensates for lamp degradation over time and automatically adjusts the length of the exposure.
Each unit is fitted with fluorescent tubes for artwork positioning and stencil touch up. The powerful suction pump ensures intimate contact between artwork and screen giving perfect exposures every time.
Each exposure unit is suitable for direct or indirect films and can be used in an open work room.
A bit simplistic for our readers or just right, what do you think?
8 Steps for Successful Screen Printing
The process of screen printing using mesh stencils made with photosensitive chemical emulsions are explained below, with helpful tips for each step to enable any artist (whether novice or expert) to achieve success in screen printing.
1. Choose or Create the Artwork to Be Screen Printed
The best way to prepare artwork to be screen printed is to have it copied onto a transparency. Most copy shops do this for a very small fee. Original artwork can be painted directly onto a transparency or onto any piece of sturdy, clear plastic. Beginners should create simple designs with fairly clear, thick lines since screen printing delicate, fine-lined artwork can be tricky.
The objective is to create what artists call a “film positive” of the artwork, which is 100 percent black on a clear background. Whether it is printed or hand-drawn, the artwork blocks the emulsion on the screen and the emulsion is washed off the design, allowing the ink to pass through the screen and transfer the design onto the T-shirt or other object that is imprinted.
2. Gather the Materials Needed for Screen Printing
Once the artwork to be screen printed has been selected and prepared, it is time to gather the rest of the necessary materials and equipment.
Object to Be Printed
The screen printing can be done on paper, on canvas, or on just about anything made from fabric, like a T-shirt, a tablecloth and napkins, a scarf, a tote bag, or simply a piece of fabric that is framed and hung as art. The object should be clean and ready to absorb the ink.
The screen frame is usually made of wood and is very tightly covered with a fine mesh material. This is the screen through which the ink is transferred onto the object to be printed. Metal screens are the most durable and stand up to many washings and printings.
Black Paper, Plastic, or Fabric
This flat black object should be large enough on which to place the frame. It is the surface on which the screen is placed to burn the image onto the screen.
Photosensitive Emulsion and Activator
The sensitizer and emulsion come separately and must be mixed together and applied to the screen. Users must make sure to mix enough to thoroughly cover the screen.
Screen Printing Ink
Users need to buy enough screen printing ink to transfer the design to the object being printed. It might be fun to choose several different colors and make several versions of the screen print art.
A squeegee is an important tool in screen printing. It is used to apply and spread the ink through the screen onto the T-shirt or other object. Squeegees are available in several different sizes, and they are made from a single piece of vinyl or from a comfortable wooden holder with a rubber blade.
3. Prepare the Frame and Screen
Some people make their own mesh screens for printing by taking an old wooden picture frame and covering it tightly with an organdy silk screen fabric, or even cut-up old gauzy nylon curtains. Users should make sure that the fabric is stretched as tight as possible and is secured thoroughly with a staple gun applied all around the frame. It is important to keep the fabric straight so that the holes in the mesh of the fabric allow the ink to pass through it evenly.
A commercially prepared screen that has already been used should be prepared for printing by washing it thoroughly with a mild abrasive to ensure that none of the holes are clogged with dirt, grease, or previously used ink. The screen should also be allowed to dry thoroughly.
4. Spread the Photo Emulsion onto the Screen
First, users should mix the sensitizer and the emulsion thoroughly according to the directions on the containers. The emulsions are light-sensitive liquid chemicals that are applied to the screen, and they become more sensitive as they dry.
The side of the screen that comes in contact with the object to be printed is known as the substrate side, while the side where the ink is placed and pushed through the screen is called the “inkwell” side. Both sides need to be covered with the emulsion mixture, and it is best to begin on the substrate side. Some people prefer to place the screen on top of a piece of black fabric or plastic. Users should pour some emulsion on the screen and spread it thinly and evenly, making sure that all of the holes are covered.
Next, users should place the screen in a dark place to dry (a closet works well). Some people like to point a fan at the screen to help it dry faster. Users need to make sure that the emulsion on the screen has dried completely, and this can take as little as a couple of hours or as long as overnight.
5. Burn the Image onto the Screen
The next steps are to attach the artwork to the screen and expose it all to light in order to burn the image onto the screen, so that the ink can pass through the screen and be transferred to the object being printed.
Attaching the Artwork
Once the emulsion on the screen is completely dry, users should lay it down on top of a clean piece of black cloth or sturdy paper, with the substrate side facing down and the inkwell side facing up. They should then lay the template with the design on it down on the inkwell side of the screen and attach it with tape. Alternatively, they could also lay a piece of clean glass on top of the artwork, while making sure that the glass is bigger than the design while still fitting inside the frame.
If the emulsion being used is highly photosensitive, it may be best to do this step in a fairly dark room so that the emulsion does not begin to react to the light until the artwork is securely in place.
Exposing the Screen to Light
Next, they should place a lamp with a 200- or 250-watt bulb about a foot or two above the screen. Professional screen printing lamps are also available for purchase, while some people like to take the frame with the artwork attached outdoors so that the UV rays of the sun burn the image. With the exposure to light, the emulsion hardens, and the area of the screen that is covered by the design does not harden. Usually 10 to 15 minutes is enough time for this process to be complete.
6. Rinse the Screen
Once the photosensitive emulsion has hardened, users should remove the artwork and rinse the screen under very cold water. This can be done in a sink, in a shower or tub, or outdoors with a garden hose. The emulsion that was under the design flakes off. It may be necessary to gently rub the area where the emulsion is being removed, using a hand or the scratchy side of a kitchen sponge. Once the screen is thoroughly rinsed, the design should be visible as a see-through part of the screen, like a stencil made out of mesh.
For the printing stage, it is a good idea to put masking tape or painter’s tape along the edges of the screen to prevent any sloppy leaks. Users should place the fabric or object to be printed down on some newspapers to protect the surface underneath. It is important to work on a flat surface so that the image is not distorted. If it is a T-shirt that is being printed, users can place some layers of paper or cardboard inside the shirt to prevent the ink from leaking through to the other side of the shirt.
When users are ready to begin the printing process, they can lay the screen down with the substrate side touching the fabric to be printed. Next, they can pour a small amount of ink horizontally across the top of the screen and use a squeegee to pull the ink down across the image, pressing the ink through the screen onto the fabric underneath. They can then move the squeegee up and down and back and forth to ensure that the ink is pressed through the screen thoroughly and evenly. The screen should be held in place, or else the image may not come through crisply. At this point, the artwork should be in printed form.
8. Cure and Clean Up
Some screen printing ink manufacturers recommend “curing,” which is placing the printed object in an oven preheated to 400 degrees F for just about 30 seconds. Other ink makers recommend ironing the back of the printed fabric to help set the ink. Users should be sure to follow the manufacturer’s recommendations on the ink being used.
Finding and Buying Screen Printing Materials and Equipment on eBay
Although there are plenty of art supply stores that sell the materials and equipment needed for screen printing, the largest selection, best prices, and easiest purchasing can be found on eBay..
Searching for Screen Printing Materials and Equipment on eBay
The easiest way to find the right screen printing materials and equipment on eBay is to go to the homepage,, type a few words into the search bar, and click Search. For example, if you are looking for “screen printing emulsions,,” simply enter that phrase. This takes you to a page with a variety of emulsions for screen printing. Follow the same procedure to search for screen printing mesh frames or screen printing squeegees.. You may want to look for screen printing kits that contain everything needed to begin screen printing, or a screen printing press for commercial use.